Norwegian state-owned energy giant Equinor has completed the drilling of an appraisal well in the North Sea but failed to find hydrocarbons.
The well 16/2-23 S, is located in production licence 265 where Equinor (42.62 per cent) is the operator with Petoro (30 per cent) and Aker BP (27.38 per cent) as partners. The drilling permit for the well was secured in October 2022. This is the 18th exploration well in this licence.
The prospect, P-Graben , was drilled about 7.5 kilometres east of the Edvard Grieg field and 10 kilometres west of the Johan Sverdrup field in the North Sea. The objective of the well was to delineate the 16/2-5 discovery and to prove additional volumes of petroleum in a graben structure from the Jurassic/Triassic with better reservoir properties, in the southern part of the Utsira High.
According to the Norwegian Petroleum Directorate’s report on Thursday, before well 16/2-23 S was drilled, the resource estimate for the discovery, proven in 2009 in reservoir rocks presumably from the Jurassic/Triassic, was between 1 and 2.9 billion Sm 3 of recoverable gas. The well 16/2-23 S encountered traces of hydrocarbons in conglomerate rock presumably from the Jurassic/Triassic with poor reservoir quality.
Furthermore, the reservoir interval in the 16/2-5 gas discovery was cored in the appraisal well, which encountered graben-filled sediments with a thickness of around 260 metres, with conglomerate rocks with poor reservoir quality. Traces of oil were encountered in an interval of around 80 metres.
Based on the Norwegian Petroleum Directorate’s statement, the well is classified as dry with traces of hydrocarbons while pressure points in the water zone confirm communication with the discovery in well 16/2-5 , made in 2009.
The result of well 16/2-23 S indicates that the resources have been considerably reduced compared with previous estimates, says NPD while adding that the revision of the volumes for the 16/2-5 discovery will be completed when final data from the well is available.
While extensive data acquisition has been conducted in the well, hydrocarbon gradients could not be established, and no liquid samples were taken. The well was drilled to a vertical depth of 2,100 metres below sea level and terminated in conglomerates presumably from the Jurassic/Triassic.
Moreover, the water depth at the site is 110 metres and the well has been permanently plugged and abandoned. The well was drilled by Odfjell Drilling’s Deepsea Stavanger drilling rig, which will now drill the wildcat well 35/10-9 in production licence 827 S, where Equinor is the operator.
The 2010-built Deepsea Stavanger rig is a sixth-generation deepwater and harsh environment semi-submersible of an enhanced GVA 7500 design. It was designed for operations at water depths of up to 3,000 metres and has a 7,500 mt loading capacity.